• acidic
  • When tap water is not sufficiently alkaline, or is even acidic and is unsatisfactory for blueing haematoxylin, a tap water substitute consisting of 3.5 g NaHCO3 and 20 g MgSO4.7H2O in one litre of water with thymol (to inhibit formation of moulds), is used to accelerate blueing of thin paraffin sections. (wikipedia.org)
  • higher
  • Before the use of any alternatives became firmly established, haematoxylin returned to the market, though at a higher price, and resumed its place in histopathology. (wikipedia.org)